Brake shoe bonding machine



Sept. '2, 1952 BARRETT v ,v 2,609310 BRAKE SHOE BONDING MACHINE Filed Sept. 10, 1949 5 Sheets-Sheet 1 INVENTOR HARRY B. BARRETT ATTORNEY Sept. 2, 1952 H. B. BARRETT BRAKE SHOE BONDING MACHINE I s sheets-sheet;

Filed Sept. 10, 1949 INVENTOR HARRY B. BARRETT AT TO R'NEY Sept. 2, 1952 3 sheets-"shut 3 Filed Sept. 10, 1949 FIG. 10.

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INVENTOR HARRY B. BARRETT ATTORNEY Patented Sept. 2, 1952 UN iTED STATES PATENT FZI 2,609,310 4 BRAKE SHOE BONDING MACHINE HarryB. Barrett, ;,S.t.;Louis, Mo. Application S eptcmber 10,1949, Serial No. 115,0 7'5 v :Glaims.

. 1 I g This invention relatesingeneral to certain new and useful improvements in brake shoe relining devices and more particularly to -a machine *for accomplishing the several operations incident to effecting securement of brakelining-to an automobile brake'shoe by means ofa 'thermosettin adhesive or the like.

It is the primary'object'oi the present inventionto provide a simple, highly ef ficient, inexpensive brake shoe relining machine which is capable of effecting a bond between brake li-ning material and a brake shoe by means-ofathermosetting adhesive or the like.

t is a further object'of thepresentdnvention to provide a brake shoe relining device of the type stated which canbe'readily adjustedtmfit a wide range of types and varietiesof brake shoes and can be so adjusted quickly and simply by the ordinary repair .shop mechanic.

It is, likewise, an-object of-the present invention to provide abrakeshoerelining device-which may be initially used, if-desired,:to-testtheibrakc shoes for various defects such as. warping, twisting, lack of concentricity, stretching, or shrinking and the like.

It is also an object of thepresent:inventionto provide a brakeshoeirelining device. which may be used, if desired, to remove previously'bonded, worn-out linings from brake shoes .in.;a :rapid, simple, and emcient manner.

' It is anotherobject of theipresentinvention to provide a brake shoe :relining. device of thetype stated in which heat is applied ,as ;directly as possible to the adhesive .-zone, .so thatzthebrake shoe and lining and particularly .the .adhesive zone therebetween will be.broughtuptoabonding temperature can be maintained '.within relatively precise limits-of controlsfor.iany;.predetermined interval of time.

It is" another object of; the-presentinvention-to provide a brake shoe-refining device eithe type stated which supports 'thegflangesg of the shoe .over a substantially true arc'wthroughout their length while pressure is applied radiallyv over substantially the entire faceof :the :brake eshoe lining, thereby preventing the shoe from .warping or otherwise deforming during thehcating :orsocalled bonding period.

It is also an object of thepresent invention to provide a brake shoerelininggdeviceof-the type stated in which substantially uniformpressure is applied during the entiregbondingyperiod, that is to-say, the pressure applying means, .in-a manner or" speaking, follows up the normal expansion of the brake shoe as the temperatureincreases so as to maintain uniformly ;a :predetermined amount of pressure within reasonablyiclose limits.

. It is a further object of the presentinvention to provide a device, ,ofpthei type stated WhiCh::Ctn: be readily adjusted :to accommodate for .difierent thicknesses of the brake. ,shoe. :flangeand vbrake lining'material in brake shoesvof a given diameter.

It is an additional.objectofthepresentinvenf n arid-p ov ded a tion to-provide a brake shoe 'relining device which may be constructed-to accommodate simultaneously -a plurality of brake shoes at one time and atone setting, so that sets of shoescanbe bonded in -asingle-operation as a group.

It is also an object of the present invention to provide a brake shoe -r'elining device' which is simple, economical, and ingged and otl ier wise highly efiicient'-in-general"operati0n.

With the above and other =obJ'ects' in-view my invention resides in the novel'ieatures of iorm, construction, arrangement, and combination of partspresentljy described and -peinted cumin :the

claims. I In the accompanying drawings Qthr-ee sheets) Figure 1 is a-topplanyiewof a brakeishoe re- .lining deviceconstructed:in.accordancef}withand embodying the present invention;

Figure 2 is-a longitudinal sectional :viewitaken along line 2-.-2of:-Figure 1; 1

Figures '3 -=and. -4are --front andrear elevational views, respectively, :ofthe :b'rake shoe bonding device; ii

Figures 5, 6, ,and 7 are fragmentary .:sectional views: taken 1 along-lines I 5&5," Ja 6', Land" 3%, respectively;of Figure 2; v

Figure 8 is a schematic- -wiring diagramnhowing the electrical connections: to .the braketshoe present inventipn;

F ure .11 is a :fr;a mentary.tront elevational iew; of themodifie i rm; Qf brakeghcei ndins d vi shown i Fis-ur ilQ;;an 1

invention.

Referring now in more detail and by reference characters to the drawings. which ill ustratepractical ,.embodiments ',.of 1 7 13 present in plate I formed prefer'a hort ,2 ess 12' by which i ma h urgeries-1 i stru ureaiflxiendine bmushi i bas plate I from'- top ,1 ottom; an-d lo'cated in the forward portion" thereof midw aybetween the j lateral edges isa way-forming slotf 3 -rorsn-ugly and slidably i accommodating a -'gu-ide tongu'e l is formed integrally with-and depending -frq'rn the under -of a slide-plate 5; *Journaled at-Hts -opposite ends; in the-- base plat e I and extending lengthwisecentrally alcng' -;the--'slot-*3, is; a 1 lead screw 1 6 which isrli'ametrally-enlarged and -exas all intermediate positions of adjustment.

3 ternally threaded, as at 1, along that portion of its length which is located within the slot 3 for extension through,and threaded engagement with, the tongue 4. To prevent longitudinal translation, the lead screw 6 is provided with a set collar 8 adapted to bear against one transverse end wall of the slot 3 and at its forward end the lead screw 6 projects outwardly from.

the base plate I and is rigidly providedwith a crank-like handle 9.

Adjacent its rearward end, the base plate I is provided with an angle member I!) having a transversely extending upwardly presented flange ll. Riveted, welded, or otherwise rigidly secured to the flange II are spaced parallel bands l2 formed of heavy gauge spring steel, spring bronze, or other similar material, and extending upwardly in a semi-circular arc, being similarly secured at their forward ends to an upstanding flange l3 formed integrally with the slide block 5, thus forming therebetween a narrow slot 14. Thus, as the crank 9 is rotated in the proper direction, the slide block 5 will be run inwardly and the bands l2 will be flexed to a semi-circular shape on a smaller radius. Since the bands l2 were made of relatively heavy material, substantial mechanical force is required and, therefore, it is preferable to provide a pair ofrstabilizing guide bars [5 rigidly mounted on and extending longitudinally along the upper face of the base plate I for sliding engagement with the lateral faces of the slide block 5, thereby preventing any tendency of the slide blocks 5 to twist or turn as it moves inwardly and outwardly responsive to rotative movement of the lead screw 6.

Rigidly mounted upon the opposite longitudinal margins of the base plate l and'extending vertically upwardly therefrom are side plates IS, the upper margins I! of which are arcuately contoured so as to enclose the bands 12 in either of their extreme positions of adjustment, as well In other words, the upper margins ll of the plate [6 along their forward portions have the shape or contour of the largest arc to which the bands [2 may be adjusted and along their rearward portions have the shape or contour of the smallest arc to which the bands [2 may be adjusted; The side plates l6 furthermore are spaced from each other, so that their inner faces will be substantially contiguous to, but not touching, the' outwardly presented lateral faces of the bands [2. Thus, the bands l2 may move with relative freedom between the side plates I6, but the space or clearance will be so small as to prevent any appreciable or measurable circulation of airor heat loss.

Mounted in facewise contact against the under face of each band 12 is an electrical heating element l8 consisting of a central relatively narrow fiat mica strip l9 conventionally provided along its longitudinal margins with a seriesof uniformly spaced notches for receiving a zig-zag winding of Nichrome ribbon 2i. Securelyheld on opposite sides of the strip 19 by rivets 22, or other suitable securement means, are relatively wider protective facing strips 2'3 also formed preferably of sheet mica or other, suitable material. At its rearward end, the heating'element I8 is set into a retaining socket 24 formed by a suitable stamped metal clip 25 rigidly mounted on the lower end of the flexible band l2. At its forward end, the heating element 18 is slidably mounted in a similar socket-forming clip 26 4 rigidly fastened upon the rear face of the flange Also disposed within the socket-forming clip 26 are compression springs 21 abutting at their lower ends against the transverse end face of the flange [3 and at their opposite ends against the downwardly presented end face of the heating element l8. Thus, each heating element I8 is resiliently urged upwardly to lie in snugfitting engagement against the band 12 with which it is associated, and, as the band 12 flexes inwardly and outwardly, the heating element I8 will accommodate itself automatically to the curvature and snugly hug the under face of the band [2 at all times so as to transmit heat directly thereinto. Mounted on the under side of each heating element I 8 and carried by the rivets 22 in depending relation thereto are conventional bimetallic thermostats 28 connected in series with the coil of Nichrome ribbon 2| and a conventional electrical input line 29 through a terminal block 30 mounted upon the upper face of the base plate I. The electrical connections are substantially conventional and are schematically illustrated in Figure 8.

Shiftably mounted in, and extending substantially vertically through, the base plate I and the flange bracket i0 is an adjustment rod 3| threaded at its lower end for receiving an adjustment nut 32 and washer 33 for abutment against the lower end of a compression spring 34 mounted encirclingly about" the lower projecting end of the rod 3! and abutting at its upper end against the under side of the base plate I.

The rod 3! projects upwardly above the base plate I and on its upwardly projecting end is rigidly provided with a cross-head 35 having an upwardly extending hinge leaf 36. Carried by the hinge leaf 3B is a hinge pin 31 projecting at both ends outwardly therefrom for hinge-form ing engagement within hinge eyes 38 formed integrally on the lower and inward end of a unitary clamping strap 39 which is substantially as wide as the combined width of the two bands l2 and extends flexibly thereover to the front of the machine. On its forward end, the strap 39 is provided with three transversely aligned hooklike reverse bends 40 spaced from each other by U-shaped clearance slots 4i.

Rigidly mounted upon the forwardly presented face of the flange I3 is a forwardly opening U-shaped pivot bracket 42 for supporting the opposite ends of a horizontally extending pivot pin 43 upon which is rockably mounted the upper ends of a split toggle arm 44. Rockably pinned to, and extending swingably between, the split ends of the toggle arm 44 at a point spaced substantially downwardly from the pin 43 is an up- 7 wardly extending clevix-like arm 45 rigidly provided at its upper end with a transversely extending bar 46 adapted to be releasably engaged in the hook-like reverse bends 40, the upper ends of the clevis-like arm 45 being adapted to fit loosely within the clearance slots 4] By appropriate adjustment of the nut 32, allowance can be made for diiferent thicknesses of the lining material and the brake shoe flange and, furthermore, the spring 34 can be adjusted to apply various clam-ping pressures, as may be required. Finally, the spring 34 will allow the strap 39 to give slightly as the temperature rises and the brake shoe, the lining, and the other parts of the device expand, thereby maintaining a practical degree of uniformity in. clamping pressure throughout the bonding eriod.

mark on the slide block i agen a-1o It will, of course, "be evident that, by turning the handle 9 in the appropriate direction, the slide block 5 may te shifted inwardly-or outwardly 11s ma "be desired. "A'sthe'sli'de block 5 is shifted inwardly, for-example, {hem the-'p'ositibn shown in full lines to the position shown in dented lines in Figure 2, theband's l2 and the heating elements -|'s earned thereby will fiex'upwardly "and inwardly to assume *a "semi-circular arcofsubs'tantially smaller-diameter. The upper race of the bas *pl'ate :I may he eenventionauy provided with a seriesei graduati-ons for visual correlation with a suitable index mark on-the slide block 5 tolndicate the diameter or the arc of the bands 12. For-example, the graduatioris c'anloe numbered consecutively from 9 to 12? and; so arranged that w en the index mark of the f'slide block 5 is aligned with the graduation bearing the number 9; the bands I2 will be disposed in an arc h'aving-a nine inch diameter. "If desired, afg'reaterrangeiof adjustment ma be provided or intermediate graduationsmay'b 'pro- "Videcl to permit intermediate fractional settings if for any reason such expedient may be deemed necessary.

At the resent time, praetie'any e11 passenger automobiles employ brake drums having iameters ranging from iiine inches to twe1ve inches and trie shoes are usually referred to in the same terms. In other "words, a" brake shoe which is designed to work within abrake drum having an inside diameter of nine inches is ordinarily "referred to as a nine "inch shoe. "Actually, the diameter of the inside arc-or under face of the shoe issubsta ntiallysmaller "than nine inches,

but isneverthel-ess or 'a-"stahd'ard' 'siz e. Thus, the

g'fa'dua'tions on thefaceo'f'the base plate [can be calibrated and numbered, so thahwhe'n the index pi"e'ci s'ely inregistration with the gf'adllati'oh "associated "with the number 9, the bands [2 "will have 'an'arc er the exactsiz'enecessafytoconform to the under face of aso-called nine inch brakeshoe.

For example, 1949 model Cadillac and Buick automobiles employed a so-eaned twe1ve inch brake shoe, that ls t'o say, a brake shoe; adapted to co-operate -with a twelve inch brake drum. Thus, if it'isdesired'to relinea Buick brake shoe,

the handle 9is 'turn'e'd until the index mark on the slide blocki'li is precisely aligned with the graduation numbered 12 and the' br'ake shoe '3 placed down'over'the bands l'2,- so that the webw of the brakeshoe' slipsdownwardly through the slot or space Hi between'th'e bands I 2.

= If "the brake shoe B is normal in shape and size, it-willfit s'nuglydown in place'onthe bands I2 without'rocking or wabbli'ng. On'the'other hand,:if the brake shoeB has been 'stretched,

shrunken, 'warped;'or twisted in actualu'se, it will not fit properly onthe bands 1 2 andth'epalrticular condition of malformation will be immediaitely revealed. In effect, the bonding machine- A, therefore, serves the very valuable function of gauging the 'brake'sh'oe B before it is relined to eliminate defective shoes.

If the brake shoeBlines"upproperly in the machine, it can then be removed and coated with an appropriate bonding adhesive byfan'y Tconv'em tional method and the pre'fdrin'edsection of brake lining'at st li'ghtly in place. There are a number of such adhesive bonding agents'available, some of which are in-theform {of heavy lviscoiis'lidui ds or pastes -and some in the form pf a slightly tacky extruded ribbon or tape;

any casefthe adhesive and lining are manuall "dimmer size.

applied td-the renew the brake shoe -and lined up so as -to be in the pr'oper position "thereon. The assembled lining garmtrake shoe are then replaced in the bonding machineA. Itm'ay'be'h'ere noted that, if desired the brake'shoe B may be initially pl'aced in the bonding machine A totest its shape 'aillfsize an'cl allowed to remain therein whilethe' adhesive and lininga: are being manual- 1y"applied. 1hus, it will be seenthat the bondir'i'g maehine h may, if desired, be used as a convenient jig for conveniently holding the brake shoewhile ithe adhesiveand liningfiare beingprelimin arily'setfin place.

-"When the brake *s-hoe B and the section of lining-"r1: are in pl'acejthe 'cl'ampingfstra'p '39 is swung forwardly "over and upon the upwardly presented arcuate'faceof the lining -and the bar 36 of the clevis arm "45- is-engaged in the bends 48. The nut 32 isthen-adjusted, if necessary, so that the clampingstrap will fit'snugly down over the brakeflining a7. 'Thereupon the toggle arm 44 is swung clown intoth'e locked position shown in-Figure'2 to draw the clamping strap 39 tightly clown; and squeeze the brake liningilt against the shoe-B withasub'st-antiaiamount of pressure. It will, of course, be :evident that 'the amount of clamping,- pressure "can '"be varied or adjusted by appropriate adjustment of the nut "32. The switch s is then turned 'on andth'e heating element I8 energized. lnasmuch as the heating element '18 is mounted directly against the under face of the-bands {2, the heat will be-very quickly transmitted through the bands; 12 directly into the -bra:l e. shoe B *andfif/O the adhesive bonding agent. Because the brakeshoe Bis held rigidly in-avise-like gripduringthe entire heating cycle, it is virtually impossible-for the; shoe or lining to warp 'OPbBQQl'Hfi otherwise distorted. Finally, the thermostat 28 may, be set to gmaintain-a-bonding temperature precisely within the optimum range -s pecified for the particular bonding, agent or adhesivebeing used, thus eliminating the danger :o'foverheating the shoe and scorching either the bonding agent or thebra'ke lining itself.

3 If desired, a modified form ofbondingmachine "A" maybe provided, as shown in 'Figure '9. The

with the previouslyide's'cribedbonding machine A,

having flexible 'llo'ands 12, which are identical 0 in every respect with the flezdbl sband 2 The jmac'hine A is, however, providedwithagas line ffflhavin'g' a'eonventionalfhand va1ve'4 8and a vertical'leg'f'fil'terminating.at-its upper end in a conventi'o'nal pipefffill. T'Eitendi'ng outwardly, on opposlte "sides of the T" Stare arcuate burner tubes 5|, 5;. Therearward'bur-ner'tube 51 is so-shapecl jand located that itw'ill'ilie in-close proximity to lthebahdsfl'Z, when' thedev'ice is adjusted for its greatest 'diametral size, on the other hand, theforward burner tubefEZ is positioned and contoured for lyi'n'g' iin'i close proximity to the bands "I 2', when the' latteriare' adjusted 'to the smallest J I he'jb'onding' macl' ifie A" ay :be connected to anyeenventionars ui-ee; of fuel-gas, illuminating ropan'e, -ior' tl1e i-like, where, for reasons of ence or-necessity; aheating-rmeans "other thanelectricity must be employed. Z It i s also possible to=provide vafurthermodiflied form :or ibonding machine; C, which comprises. a 'irelatively -large rectangular base plate .providedatits-fourqcorners-withlegs -54. Dis- -.pos ed; centrally within theibaseiplate 53is a slide block 5' operativelymounted on a1lead screw 1' which projects outwardly'fromrtheiforward 'edge 7 of the base plate 53 and is rigidly provided with a handle 9', all of which elements are substantially similar to the previously described slide block 5, lead screw 1, and handle 9. I

Rigidly secured upon the slide block and extending transversely across the upper face of the base plate 53 for shiftable movement therealong is a mounting bar 55 for rigidly supporting the forward ends of four tandem-connected pairs of arcuate bands l2", the latter being substantially similar to the previously described bands l2 and being rigidly mounted at their rearward ends in uniformly spaced transverse alignment adjacent to the rearward edge of the base plate 53. Each pair of bands I2" is provided with a clamping strap 39' substantially identical with the previously described clamping strap 39 and adapted for releasable engagement at its forward end with a clamping bar 46' mounted in a clevis-arm 45', which is,'in turn, operatively connected at its lower end to a toggle arm 44.

The modified form of bonding machine C is, in effect, a multiple size bonding device adapted for use in substantially the same manner as the previously described bonding machine A except that a set of four brake shoes can be bonded in a single operation. Obviously, where desired, it is possible to provide multiple size bonding devices adapted to operate simultaneously upon any desired number of brake shoes.

It has also been found, in connection with the present invention, that the heating elements l8 of the bonding machine A may be wired or connected in a modified form of circuit shown in Figure 12. In this modified arrangement, each pair of heating elements I8, together with the thermostat 26 and switch s, is connected through an auxiliary switch 3', of the double-throw, double-pole type, in such a manner that the heating elements 18 may be alternatively connected in series or in parallel. When connected in parallel, the thermostat 2a is by-passed and the temperature will be almost twice the normal desired temperature. This type of circuit arrangement makes is possible to place worn brake shoes in the machine. At such elevated temperature, the bonding agent will be carbonized and, therefore, the bonding machine A, when thus wired, can be used for the additional purpose of removing old, worn brake linings from brake shoes prior to the relining operation. The worn brake shoe is placed in the bonding machine A and the auxiliary switch s moved to the parallel-connected positions (as shown in Figure 12) and the main switch 8 turned on. Almost immediately the temperature rises and the bonding agent is destroyed. Thereupon, the worn section of brake lining material can be knocked loose with a light tap of a hammer. It has been found that the temperature at which the bonding agent is effectively destroyed does not in any way damage the brake shoes themselves. After removal of the worn lining has been completed, the auxiliary switch s may be moved to its other or series-connected position, whereupon the temperature is under control of the thermostat 26 and is held within optimum bonding range.

It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the brake shoe bonding machine may be made and substituted for those herein shown and described withoutdeparting from the nature and principle of my invention.

8 Having 'thusdescribed my invention, what I claim and desire to secure by Letters Patent is:

1. A-brakeshoe relining machine comprising a base, a flexible arcuate member, said member being fixedly attached at one end to the base and being adjustably mounted at its other end on the base, means for shifting the adjustably mounted end of the arcuate member toward the attached end for varying the curvature of the arcuate member, and a flexible clamping band operatively mounted on the base in outwardly spaced concentric relation to said arcuate member.

2. A brake shoe; relining machine comprising a base, a flexible arcuate member, said member being fixedly attached at one end to the base and being adjustably mounted at its other end on the base, means for shifting the adjustably mounted end of the arcuate member toward the attached end for varying the curvature of the arcuate member, and a length adjustable, flexible clamping band operatively mounted on the base in outwardly spaced concentric relation to said arcuate member.

3. A brake shoe relining machine comprising a base, a block adjustably mounted on the base, a flexible arcuate member anchored at one end to the base-and at the other end to the block, and a flexible clamping band releasably overlying the outer peripheral face of said arcuate member.

4. A brake shoe relining machine comprising a base, a block adjustably mounted on the base, a flexible arcuate member anchored at one end to the base and at the other end to the block, and a length adjustable, flexible clamping band releasably overlying the outer peripheral face of said arcuate member.

5. A brake shoe relining machine comprising a base, a block slidably mounted on the base, means mounted on the base for sliding the block into any selected position of adjustment within the range of movement of the block along the base, a pair of spaced parallel flexible metallic bands rigidly mounted at one end upon the base and extending outwardly therefrom in a substantially circular arc and being rigidly fastened at the other end to the block for supportive engagement against the under face of a brake shoe, the space between the bands being of substantial width to accommodate thebrake'shoe web, a flexible metallic clamping band swingably mounted at one end to the base adjacent to the point of attachment between the base and the bands, said clamping band being adapted to extend outwardly over and around the outer face of the brake shoe when the latter is supported by the spaced parallel bands, and means on the block for optionally engagin the other end of .the clamping band for drawing the clamping band tightly down clampwise upon the brake shoe. i 1

HARRYWB. BARRETT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,926,022 Barrett Sept. 12, 1933 2,416,427 Bonawit Feb. 25, 1947 2,489,496 OBrien 'Nov. 29, 1949 2,494,281 Batchelor Jan. 10, 1950 

1. A BRAKE SHOE RELINING MACHINE COMPRISING A BASE, A FLEXIBLE ARCUATE MEMBER, SAID MEMBER BEING FIXEDLY ATTACHED AT ONE END TO THE BASE AND BEING ADJUSTABLY MOUNTED AT ITS OTHER END ON THE BASE, MEANS FOR SHIFTING THE ADJUSTABLY MOUNTED END OF THE ARCUATE MEMBER TOWARD THE ATTACHED END FOR VARYING THE CURVATURE OF THE ARCUATE MEMBER, AND A FLEXIBLE CLAMPING BAND 